Daily Trivia - The Zoom Lens on iPhone 15 Pro Max

Android users have long had the periscopic zoom camera on their phones. Top players like SONY even have an actual optical zoom range periscopic camera, and Huawei pulled off a few cool tricks on their flagship phones too before facing a ban.

So, here comes a question: Did Apple just “reinvent” the periscopic zoom lens again?

Actually, THEY DID.

Wait, let me explain.

Let’s start from the beginning.

A zoom lens requires a lot of light from a distant object. A lot of light means a big lens, which requires a longer light path to focus on the sensor. You can’t fit a long lens on a phone, so we use a periscopic lens, just like binoculars, to reduce the light path.

So, what is the innovation that Apple introduced?

Other competitors use two pieces of 90-degree reflecting mirrors and a bunch of lenses sandwiched in between.
The extra lens in between is used for focusing and image stabilization.
The light path is still long, and you still need a lot of vertical space in the phone.
Apple uses a single prism to achieve four-time reflection (2 TIR and 2 AR), greatly reducing the size and length of the zoom module.
The prism needs to be super precise because now all four surfaces need to align to the dot, compared to the Android approach, which only aligns one surface.
The focus is achieved using sensor shifting, and X/Y axis image stabilization is also done using sensor shifting.

There are many details to explore in the Apple patent filed in May 2022 (https://patentimages.storage.googleapis.com/d9/db/98/56b9e58c2d18e9/US20220163706A1.pdf).

If you search for Apple patents on periscopic lenses, you will find quite a number of patents since 2021. They’ve been trying to do this the Apple way:

Making things simple Making things cheaper

Compared to the Sony Xperia zoom lens, you can see that Apple’s design is much simpler but required a lot of research to get it right. For example, Apple needed to add two cut lines on the prism to prevent full TIR and a total of eight layers of coating on the prism itself.

If you want more daily trivia like this, please comment and let me know :D

每日小知识 - iPhone 15 Pro Max 上的变焦镜头

Android 用户很早就拥有了他们手机上的潜望镜式变焦相机。像索尼这样的顶级厂商甚至拥有一个真正的光学变焦范围潜望镜相机，而在被禁之前，华为也在他们的旗舰手机上做了一些很酷的事情。

所以，这里有一个问题：苹果是否再次“重新发明”了潜望镜式变焦镜头？

实际上，他们做到了。等等，让我解释一下。

让我们从头开始。